1. Field of the Invention
The present invention relates to a device for grinding cutting tools having straight and spiral grooves. The device includes a workpiece or tool spindle which is rotatable in a housing and can be set in a combined turning and advancing motion. A roller capable of engaging the outer surface of the spindle with a certain definable contact pressure is rotatable and adjustable about an axis which extends in radial direction relative to the spindle. The device further includes a locking unit for fixing the angular position of the spindle.
2. Description of the Prior Art
Devices of the above-described type are used in connection with conventional tool grinding machines. Such a device includes a spindle which is mounted so as to be capable of rotating and reciprocating without play for receiving the tool to be ground. The pitch of the spindle necessary for generating the advance of the tool during grinding is adjustable by changing the setting angle of the roller which is in frictional engagement with the spindle. A device of this type is disclosed, for example, in German patent No. 32 32 689.
If a tool having several spirally extending cutting edges, for example, a plain milling cutter is to be ground, it is necessary after the first tool cutting edge has been ground to turn the spindle for grinding the other tool cutting edges by a certain angle from its angular position for the first tool cutting edge which corresponds to a zero plane intersecting the longitudinal axis of the spindle. Compare, for example, U.S. Pat. No. 2,503,926. For this purpose, it is necessary to separate the frictional engagement between spindle and roller and to move the spindle into the new angular position by means of the locking unit which acts as an indexing unit. In the new angular position, the spindle is again radially and axially fixed by means of the locking unit. For the subsequent grinding of the new tool cutting edge, the roller is placed on the spindle and is separated after the locking unit has been mounted. This is done by means of separate manipulating devices which are structurally compensated and require time-consuming adjusting operations which are also time-consuming.
It is, therefore, the primary object of the present invention to provide a device of the above-described type which is simple with respect to construction and operation. Specifically, a device is to be provided which, while still being free of play, makes it possible to carry out more quickly and safely than in the past to adjust the spindle in accordance with the graduation of the cutting edges of the tool to be ground. In addition, operating errors are to be made virtually impossible.